Supernatural Hearts
by ScorpioGirl1987
Summary: After the darkness is let loose, Castiel tells the Winchesters of the keyblade, a failsafe weapon to be used in case the Mark fails to contain the darkness. The Winchesters must team up with Sora and Riku, two keyblade masters from another dimension to defeat the darkness once and for all.


**So, did the end of the Supernatural season 10 finale seem Kingdom Hearts-y to anyone else?**

… **I could not resist. I made a crossover! Haha!**

 **Anyway, I do not own Supernatural or Kingdom Hearts. They belong to the CW and Square Enix/Disney respectively.**

 **Also, this takes place after the season 10 finale of Supernatural, and Kingdom Hearts Dream Drop Disntance.**

After the darkness was let out, the first thing the Winchester brothers did was get the Impala out of the mud hole. The second thing they did was call Castiel. They couldn't reach him. Instead, Crowley answered.

"Your boyfriend just tried to kill me." Crowley said, slightly irritated.

Dean's left eye started twitching. "He. Is. Not. My. Boyfriend. Now, where is he?"

"Wow that went over your head didn't it?" Crowley remarked. "My dear mother put a spell on him to kill me. Fortunately, I knew the counter spell. He's out cold."

Dean exhaled sharply and started driving. "Ahem. Um…listen, I uh…don't suppose you would know anything about the Darkness, would you?"

Crowley looked out the window, eyes widening in horror. "What the bloody hell did you do?"

"What did _I_ do?! You, Sam, Castiel, and your bitch of a mother cured me of the mark, and it released the frigging Darkness!" Dean exclaimed angrily.

"What the hell were you expecting? That the Darkness would just evaporate?" Crowley shrugged.

"You know, it would have been nice if you or Cas mentioned this little fact oh, say, _before_ you decided to cure me of it!" Dean argued.

"I thought Castiel _did_ mention it and you and your giant of a brother didn't care!" Crowley shot back. "You two have an extremely unhealthy codependency to each other."

"Do you know how to stop this thing, or not?" Dean snapped. Crowley was getting on his last nerve.

"Nope. Sorry, mate. You two are on your own on this one." Crowley hung up, sighed, and vanished.

Dean tossed his phone aside and fumed. "Great. I can just hear the other hunters saying 'Damn you, Winchesters!'."

Sam felt guilty. "Dean, I'm sorry. If I'd known…"

"Don't apologize, Sam." Dean replied, looking straight ahead. "You didn't know."

Sam exhaled sharply. "'Course this wouldn't have happened if Castiel told me about this."

"He's an assbutt." Dean said simply.

"Who's an assbutt?"

Sam and Dean turned around to see Castiel in the backseat. Dean pulled the car over. "You are for not telling Sam about the Darkness!"

"That's because I didn't know all the details." Castiel admitted. "I was young when it first…appeared and when Lucifer got the mark. I only knew that it was a very bad thing."

Dean exhaled sharply and sank low in his seat. "So, I guess this means you don't know how to stop this thing."

"Let me see what I can find out…if my brothers and sisters are willing to speak to me after everything that's happened." Castiel said, and vanished.

Dean just nodded, restarted the car, and headed towards the bunker. He turned on the radio, and the song "Hello Darkness, My Old Friend" started playing. "I love how the radio always just seems to play fitting music."

Sam just scoffed lightly and shook his head.

XX

The next morning, Castiel appeared at the Winchesters' kitchen table. "I found Joshua. He was the only one willing to share with me."

"Good old Joshua…" Dean muttered.

"Yes. Anyway, he said there are people who can help." Castiel went on. "The Darkness is an entity. It can enter a human body even without the mark. God created a failsafe weapon in case the Mark and the First Blade failed: the keyblade."

Sam looked up as if to remember something. "Wait a minute…"

"What?" Dean turned to his brother.

Sam stood up. "I remember reading something about it in one of the books in the library. Be right back." He ran off.

Dean turned to Cas. "So, where do we find this keyblade?"

"You can't." Castiel replied. "They're very specific. Only someone with a strong heart is able to wield the keyblade."

"So, do you know anyone who can?" Dean asked.

"I may know someone who knows." Castiel replied. "Give me twenty-four hours." He vanished.

"Where'd Cas go?" Sam asked, as he reentered the room carrying an old book.

"To find someone who wields a keyblade, whatever the hell that is." Dean answered.

"Well, to summarize…" Sam put the book down in front of Dean and opened it. One page showed a picture of a giant key. "A keyblade is a key, a magic wand, and a sword all rolled into one."

"So like a superweapon?" Dean asked with interest.

Sam nodded. "You can perform magic spells with it, and in addition to opening up any lock, a keyblade can also unlock people's hearts."

"'Unlock people's hearts'?" Dean asked in confusion.

"Yeah, that part's kind of confusing." Sam shook his head. "But, I don't think it means the body part. It means like…your feelings, your emotions…like if someone breaks your heart, they're not literally breaking your heart."

Dean nodded to show he got it. "Right. What does that have to do with the Darkness, though?"

Sam paused. "That I do not know."

"Well, first we need to find out what caused the Darkness in the first place." Dean said.

"I think I can help with that." They turned to see Joshua sitting at the table.

"Joshua?" Both Dean and Sam said simultaneously.

Joshua nodded. "The Darkness was created from the darkness in the hearts of Lucifer and his followers. Their anger, hate, rage, envy…"

"Douchebagginess." Dean supplied.

"Exactly." Joshua replied. "That is why the Mark was created. However, God knew one day the Darkness would be released. That is why He created the keyblade. Only those with strong hearts can wield such a powerful weapon."

"So…how exactly do we wield one?" Dean asked.

"I'm afraid your heart's not strong enough, Dean, and it's not because of all the bacon cheeseburgers and alcohol you consume." Joshua spoke with hardly any emotion. "Sam, I'm afraid yours isn't, either."

Sam scoffed. "Perfect."

"Speaking of God, don't you think it's about time He steps in?" Dean jumped in. "I mean…this is as bad as it gets."

"He wants you to correct your mistake." Joshua turned to Sam.

"And I can do that with the key bearers' help?" Sam asked.

"You can." Joshua nodded.

"Okay, one more thing, what does the keyblade have to do with the Darkness?" Dean asked again.

"In order to get rid of the Darkness once and for all, one would have to consume it…and then the keyblade would be used to unlock that person's heart and end the Darkness once and for all." Joshua explained. "Good luck." With that, he vanished.

Dean let out a sharp breath and leaned back. "Well, I tell you one thing."

"What?"

"I feel sorry for the poor bastard who has to help us."

XXX

Sora and Riku headed up to Yen Sid's tower. "So, what do you think he wants with us now?"

"I dunno, Sora, but it must be big if he sent for both of us." They entered the tower where Yen Sid and King Mickey waited for them. "Master Yen Sid, King Mickey."

"Sora, Riku. This mission will be your most unusual yet." Yen Sid started. "An unidentified darkness has spread over a vast world by name of America."

"Wait, I thought we closed all those keyholes?" Sora asked in confusion.

"That world wasn't consumed with darkness when you went on your first journey." Yen Sid explained. "Two supernatural being hunters accidentally let loose the darkness. They need your help."

"Okay! We'll definitely go." Sora exclaimed.

Riku nodded. "So you want us to work with these hunters?"

Yen Sid nodded. "Their names are Sam and Dean Winchester. They are brothers."

"Okay! Once we get there, we'll ask around…"

"It may not be so easy, Sora." Yen Sid interrupted. "Since it is a vast world, not everybody knows one another. The Winchesters have made a lot of enemies over the past decade. Some may use you against them, others may kill you before you have the chance to meet the Winchesters."

Sora gulped. "America does _not_ sound like a friendly place."

"Cid and Leon have been alerted of this mission." Mickey stepped in. "They are preparing identities for you two as we speak."

Riku nodded. "Okay. Aren't you coming with us, Mickey?"

"Talking animals are very strange to their world." Mickey explained. "If I were to go with you, I'd probably be dead or experimented on within ten minutes."

"Okay, remind me again why we're going to this world?" Sora spoke up.

"To get rid of the Darkness." Riku deadpanned.

"Well, I know, but…"

"Master Yen Sid, is there any way you can show us what the Winchesters look like?" Riku asked, interrupting Sora.

Yen Sid waved his hands and created a vision from magical mist. Sora and Riku saw two men, both with brown hair, sitting at a table drinking…something. "The man with the longer hair is Sam. The other is Dean."

Sora and Riku nodded. "We won't let you down."

"Good luck, fellas!" Mickey smiled.

XXX

Once at Radiant Garden, the two friends met up with Cid and Leon at Merlin's house. They were waiting with ID cards and money.

"Glad you two could make it." Leon greeted them. "These will be your identities while you're in America. Sora, you will be Sora Naka; Riku, you will be Riku Wantanabe. It'd be weird in that world if you only had one name…unless you're an angel or a demon, which you two are not."

"Wow." Sora studied his ID. "Why does it say I'm eighteen years old?"

"Because children under eighteen wandering around will usually be sent to orphanages or foster homes." Cid replied. "We wanna make sure you two keep as low a profile as possible."

"Makes sense." Riku pocketed his ID and money. "I'm guessing our clothes and hair will change once we're there."

"You guess correct." Cid replied. "Also, there are certain rules you need to follow. First off, do not trust every single person you meet… _Sora_."

"What?" Sora shrugged innocently.

"Second, listen to everything these Winchesters tell you. They'll teach you all about how to survive in that world." Cid went on. "Third and most obvious and important, _do not_ let on that you're from another world. People will think you're crazy."

"They never have before." Sora argued.

"They will in this one. Trust me." Leon said firmly. "All right, that's everything. Good luck."

"Best of luck." Cid added.

"Thanks, guys." Sora smiled and nodded. He and Riku set off.

"Well, at least we won't be separated this time." Riku said, smiling.

Sora nodded. "Yeah."

They flew for hours until they came across a huge world completely covered in darkness. "Found it."

"Whoa!" Sora leaned forward, eyes widening with awe. "Holy crap. They weren't kidding."

"Seriously." Riku flew the gummi ship down. They heard a loud humming sound, and another sky vessel came from their left. "The hell is that thing?" He was about to turn, but the wing of the vehicle hit the back of the gummi ship causing them to lose altitude.

"WHOA!" Sora held on tight as they tumbled towards the ground. "RIKU, DO SOMETHING!"

"I'M TRYING!" Riku yelled frantically. He fiddled with the controls. "I can't control this thing!" They continued falling. "Sora…this may be the end. I want you to know that…I love you like a brother."

"Riku, I peed in your water bottle that one time we were at the beach." Sora confessed. "I told you it was a dog, but it was really me."

Riku did a double-take. "What?!"

"I'm sorry!" Sora exclaimed in anguish, tears streaming down his face. The ship hit the edge of a cliff, tumbled, and crash landed into the forest below. Riku and Sora both lost consciousness.


End file.
